Parámetros astrofísicos fundamentales de 6 cúmulos de la Nube Mayor de Magallanes en el rango de transición entre 200 y 700 millones de años

PIATTI, ANDRÉS E.; BICA, EDUARDO; GEISLER, DOUG; CLARIA OLMEDO, JUAN JOSÉ

La Plata

Congreso; Reunión Anual de la Asoc. Argentina de Astronomía; 2003

Complementing our recent Washington photometric studies on intermediate age and young Large Magellanic Cloud (LMC) clusters, we present in this work new results for 6 previously unstudied star clusters in the transition range 200-700 Myr. We study NGC 1836, NGC 1860 and NGC 1865, which are projected on the LMC bar; SL 444, also located in the central disc but outside the bar, and LW 224 and SL 548, both located in the outer disc. We derive ages and metallicities from extracted T1 versus C-T1 colour-magnitude diagrams (CMDs), using theoretical isochrones recently computed for the Washington system. For the metallicity determinations, these CMDs are particularly sensitive. We also estimate ages and metallicities of the surrounding fields of NGC 1860 and NGC 1865 by employing the δT1 index and theoretical isochrones.